DE102008030809A1 - Method for water recovery and/or cleaning of wastewater, by carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh for self-effacement of coarse material, which is washed for avoiding faecal sludge - Google Patents

Abstract

The method comprises carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh (2) with a mesh size of smaller than 5 mm for self-effacement of coarse material, which is washed for avoiding faecal sludge from biologically pre-cleaned wastewater. The wastewater is passed through in a cascade-like operation of three separate, biologically active steps. The wastewater is reduced from the undissolved portion of the oversize material. The wastewater with particle size of smaller than 5 mm is subjected over a cross-flow cleaning in the area external of the mesh. The method comprises carrying out pressure less biologically active step in a self-tensioning, finely-meshed mesh (2) with a mesh size of smaller than 5 mm for self-effacement of coarse material, which is washed for avoiding faecal sludge from biologically pre-cleaned wastewater. The wastewater is passed through in a cascade-like operation of three separate, biologically active steps. The wastewater is reduced from the undissolved portion of the oversize material. The wastewater with particle size of smaller than 5 mm is subjected over a cross-flow cleaning in the area external of the mesh for denitrification with anoxic milieu. The biologically active bacteria sludge and completely nitrified wastewater are led with nitrate oxygen. The nitrate is converted into gaseous nitrogen through denitrification and the biologically degradable carbon is converted into carbon dioxide. The wastewater is completely freed from nitrogen compounds. A further denitrification reaction is reached by alternate aeration and by minimizing the air entry. The entry of oxygen in the air is controlled over a filtrate quantity measurement. A physically technical bleaching and hygienisation are carried out after physical elimination of all biologically non-degradable substances over ultrafiltration membrane. The wastewater flows out from the first container (3, 7, 9) or basin/first hollow chamber either in the free mirror in the following biological area and is brought in corresponding height difference through pumps on the level of the biological area. A pump is required for simple maintenance external of the network in the denitrification area. The inflow is carried out in the biological area in the free mirror and the reaction pump is present in the second or later container or basin. The pump in each case guarantees sufficient recirculation of the wastewater and upstream denitrification. The resultant filtrate is brought either hydrostatically or over a further self suctioning conveyor unit (4) with slight low pressure to the utilization grade. The membrane in the requirement is automatically washed back without restriction of the operation of the plant directly during the operation with chemicals or filtrate. In the first step, the carbon decomposition is carried out with biological heavily degradable substances like hormones and endocrine material and is integrated over the biological phosphate elimination and also an alkaline and acid phosphate precipitation, which is regulated over the filtrate quantity and pH value. In the second step, the biological non-degradable substance and the complete bleaching are carried out through the physical elimination (adsorption over active charcoal, adsorber resin or aluminum silicate) with subsequent additional physical hygienisation with UV radiation. An INDEPENDENT CLAIM is included for a device for water recovery and/or cleaning of wastewater.

Description

The Development concerns a procedure that meets the qualitative requirements for wastewater free Houses and Settlements met and built in any size can be.

Sewage Treatment plants serve for the purification of wastewater. In the task, "sewage-free houses and Settlements " enable, have the one for this required technical equipment much more extensive requirements to fulfill.

It It is known that organically polluted wastewater is aerobically-biologically purified become. The pre-cleaning is done i. A. mainly on sedimentation tanks in multi-chamber pits, it falls to be disposed of fecal sludge at. Separation of biologically active sludge also occurs by settling or over Micro- or ultrafiltration membranes.

It is also known that organically polluted wastewater semi-automatic or fully automatically controlled via mechanical biological processes, SBR processes, trickling filter processes, Fixed bed process and u. a. Membrane biological process purified become. Only the membrane processes are able to target one To carry out germ reduction, around the for hygienizing the required values at the outlet.

One known method with microfiltration membranes has in a pre-cleaning an outside ventilated sieve tube or net with support tube for restraint of sanitary ware or similar, non-biodegradable wastewater ingredients. This sieve tube or net with support tube tends to mix with activated sludge due to insufficient cleaning effects and wastewater ingredients such as hair or other, for clogging To add tending thread-like substances. A regular cleaning of these mechanical prepurification units in an unsanitary Environment is required. The same applies to the internal circulation of the pre-cleaning.

A continuous return promotion from activated sludge in the Vorreinigungsraum and an upstream Denitrification is due to the risk of blockage of the sieves and Networks thus not or only very limited possible.

The Raw sewage gets outside of the sieve tube or net with support tube in the pre-cleaning. In order to collect sanitary articles and other non-sewage substances in the primary clarifier. This makes a regular cleaning the basin and disposal of the resulting fecal sludge necessary.

The Precleaning promotes while wastewater ingredients greater than 8 mm in the membrane container. Particles of this size are while eligible, set however the membranes too.

This known method with microfiltration membranes works predominantly with modified, single and double-walled fuel oil tanks as Vorreinigungs- and Biology basin. These tanks are bulky and heavy, u. U. susceptible to corrosion and not installable in every pit or room.

These container have as well only a small height of about 1.6 m. This also results in a lower process liquid Level in the containers from 0.8 to 1.4 m, resulting in a relatively poor oxygen utilization associated with elevated specific energy demand results.

Tries, double-decker Membrane modules in this container incorporate, have proven to be a faulty design.

Around the pre-treated wastewater from the pre-treatment tank into the biology / membrane stage to promote used a mammoth pump. This pump is limited by the head, which only a limited Emptying the container possible is. Furthermore it also tends to clog in this particular design.

Farther this process is operated with rigid plate membranes, the also for frequent clogging tend. To achieve such clogged microfiltration membrane modules a weight of almost 70 kg. In this condition they are manual from i. A. to remove difficult to reach containers and for the cleaning completely disassemble. These are one for the maintenance staff unreasonable work and a time and cost consuming Maintenance step.

For taking out the filter module has contrary to the description in the known Method of lowering the level proved to be mandatory.

Of the perennial Operation of such microfiltration membranes also has shortcomings such as leaks and embrittlement shown at the filtrate collector by the often necessary maintenance with complete decomposition of the membrane modules were reinforced. This often occurs significant transgressions the limits. The required sanitation is not guaranteed. Therefore, in the meantime, an additional ultrafiltration downstream.

The for the Manufacturing used material also shows weaknesses in the Eyes (locking eyes) for the Module connecting bolts to aging material and sizing are due to notch effect. The consequences are frequent Breakages with leaks and, in turn, leaks occur and transgressions of all limits.

by virtue of the unsafe disinfecting effect are to ensure sanitation additional ultrafiltration modules nachzuschalten.

The Microfiltration plate membranes are not backwashable and must be removed for cleaning become. Rückspülversuche The manufacturer of the microfiltration system proved to be ineffective.

These Plate modules have based on the thickness of a plate on the filter surface high weight combined with low packing density.

Modular advanced microfiltration house wastewater treatment plants require an energy-intensive, frequent back and forth of the wastewater to be treated in order to evenly load all plant components to ensure. As a result, there is no time for the fine-bubble ventilation at full load because the blowers for the Promotion needed which affects the cleaning performance of the entire household wastewater treatment plant effect. The modular extension hinders the cleaning process and reduces the result.

essential Disadvantage in the operation of the known system is that the membrane modules tend to block.

in the Framework of the research project "Development and Testing of water and material cycles for sewage-free Property "promoted by German Federal Ministry for Education and research have different procedural and material engineering or qualitative problems with equipment available on the market.

The invention is based on the object
to design a single- or multi-stage wastewater treatment and water recovery so that, depending on the number of process steps, the requirements for a water for human use in accordance with the EU Drinking Water Ordinance Annex 1, Part 1 or Part 2 are safely met.

Furthermore, the special requirements for the protection of groundwater from nutrients, in particular nitrate should be met, in particular the conditions for complete nitrification (<1 mg NH ₄ -N / l) and largely denitrification (<10 mg N _ges / l) met become. Also, hydraulically sufficient reserves are to be present and the system should be energetically-economically operated, at no time fecal sludge is obtained.

The solution This object is achieved according to the invention by that described in claim 1 Method or by the device described in claim 11.

The invention will be explained in more detail below with reference to an exemplary embodiment:
Raw sewage is fed through a pipe ( 1 ) in a self-exciting fine-meshed (small 5 mm hole / mesh) mesh ( 2 ). The diameter of the net is equal to the size of the entry opening of the pit or container ( 3 ) customized. As a result, this network can be removed for the purpose of emptying. The fine-meshed net is introduced in the inlet area of the system and retains coarser substances. The retained substances are washed by biologically pre-treated wastewater and thereby reduced to the non-dissolving sieve residues. This prevents fecal sludge.

Via a cross-flow cleaning by air entry ( 5 ) enters wastewater with particles smaller than 5 mm the space outside the net with predominantly anoxic milieu in which the further, upstream denitrification takes place. Alternatively, the wastewater flows either in the free-flowing level in the following biology room or it is by a pump ( 4 ), the z. In the container ( 3 ), the pre-treated wastewater via the line ( 6 ) in the container ( 7 ) lifted.

In this room reaches z. From containers ( 9 ) also biologically active bacterial sludge and fully nitrified wastewater with nitrate oxygen from biology ( 7 ) or membrane container ( 9 ). The nitrate is converted by denitrification into gaseous nitrogen. As a result, the readily biodegradable carbon is converted into CO ₂ and the wastewater is almost completely freed from nitrogen compounds. Further denitrification reactions are carried out in the containers or chambers ( 7 ) and ( 9 ) or other containers or chambers by alternating aeration ( 8th ) or ( 10 ) and by minimizing air entry via simultaneous operations.

The Wastewater can from the first container or basin / the first pit chamber either in the free-level in the flow through the following biology room or it will be at corresponding height difference by pumping brought to the level of the biology room.

Provided a pump is required, this is located separately outside of the network in the denitrification room. This will be a simple maintenance allows.

In the case, that the inflow into the biology room in the free-level takes place the recirculation pump in the second or a later container / basin. The pump has in each case at the same time the task for a sufficient Recirculation of the waste water to ensure and upstream denitrification.

Of the Biology room is as well as the area of upstream denitrification or the area of solid-liquid separation following the biology room with independent working, alternating ventilation units fitted. The entry of the atmospheric oxygen via a Filtratmengenmessung and is about a telemonitored Control unit regulated. The fan blower will be close installed in order to avoid pressure losses via supply lines.

The Solid-liquid separation over Ultrafiltration membranes. It is used to save energy in small Plants at least twice the membrane area of comparable plants Installed. This can significantly reduce the filtration time and the service life of the membranes significantly extended and minimized energy requirements become.

Clogging and sludge-free ultrafiltration membranes ( 11 ) with highest packing density used. These are rebuilt and installed in such a way that the height to be flowed through is lowest and the flow resistance is lowest and a high bubble density can be generated, which additionally avoids the risk of clogging.

The resulting filtrate is either hydrostatically or via a self-priming delivery unit ( 12 ) brought to the place of use with low negative pressure.

The Filtrate can be used as either toilet or irrigation water or if adequate Quality depends on Raw sewage also directly as process water in various other Fields of application can be used. It stands out against microfiltration membranes through higher ones Bacterial and viral retention out.

The Membranes can If required, the operator can also be backwashed with chemicals directly from the operator. An automatic, regular backwashing of the Ultrafiltration membrane with filtrate is possible. In both cases the operation of the system is not restricted.

Depending on the purpose of the recycling, the filtrate may be treated by physical-biological processes into "Water for human consumption according to EU Drinking Water Regulation, Annex 1, Part 1 or Part 2". This is done z. Example by adsorbing to activated carbon, clay minerals, adsorbent resins or mixtures ( 13 ) thereof in connection with UV irradiation ( 14 ).

By the method biologically active solids can be obtained and since these are almost completely mineralized, they can ver as a composting accelerator or to improve the garden soil be evaluated.

The accumulating residue can be easy waste technology be disposed of. However, this is usually not necessary. The process plant consists of at least 3 separate, biologically active containers and allows thereby a cascade-like operation.

The Procedure fulfilled the prerequisite for the carbon limitation, d. H. it can grow more bacteria as nourished with raw sewage and can be kept alive. This will reduce the accumulated excess bacterial mass minimized.

The container are preferably in the folded state, at the lowest Volume and weight transported and locally to full volume opened.

The container the plants are z. B. foldable as boxes and thus in each existing pit and any existing space transportable and adaptable to the respective sizes. The containers can also be used for sealing leaking pits.

The container hydrostatic pressures above 1 bar stand and are with, depending on the application, water or chemicals resistant inliners absolutely waterproof lined.

by virtue of the volume-related low weight of the containers are for the Installation No heavy machinery or lifting equipment required.

With the system it is possible to accommodate up to 50 m ² / m ³ biology volume in the smallest space, the highest filter surface concentration and thus the highest hydraulic load capacity.

The to be filtered wastewater is always sufficiently cleaned and thus achieves the solid-liquid separation over the Membranes very long service life. The resulting filtrate can with minimum effort to COD values below 5 mg / l are cleaned. The process works without pressure.

The process is multi-level. The 1st stage includes carbon degradation including substances that are difficult to biodegrade, such as hormones and endocrine disruptors, as well as full nitrification and further denitrification. If the filtrate is to be introduced into a stagnant body of water, it is also possible to integrate an alkaline or acid phosphate precipitation beyond the biological phosphorus removal. As a result, P _ges values <0.02 mg / l can be maintained. This limiting factor is safely adhered to in order to avoid eutrophication (algae formation) and allows the production of drinking water from a stagnant water.

The Water from the first stage can be safe for health and without danger for the Groundwater for irrigation or for toilet flushing be used. The phosphate precipitation will over the filtrate and the pH are controlled.

The 2nd stage involves the physical elimination (adsorption via activated carbon, Adsorber resins or aluminum silicates) of all coloring and all non-biodegradable substances and complete decolorization (COD <1 mg / l) followed by additional decolorization physical sanitation with UV radiation. After that are no bacterial loads more noticeable. The removal of viruses is over 99.9999%. The water from the 2nd stage can be used for showering, bathing, washing clothes, Cleaning etc. are used.

The effectiveness the method according to the invention is substantiated by the values given in the table below.

The 3rd level is a pure security level based on membrane technology combined with another physical sanitation with UV rays for the case that the water is also drunk or used for cooking shall be.

This Procedure is appropriate, in addition to domestic Wastewater also other organically contaminated wastewater to the highest qualitative requirements to prepare and is also for the degradation of poorly biodegradable organic substances such as hormones, medical remnants or textile mill wastewater suitable.

Claims (19)

Process for water recovery or for cleaning of waste water, where the wastewater in a cascading operation passes through at least 3 separate, biologically active steps and each without pressure first in a self-tensioning, fine-meshed mesh with a mesh size less than 5 mm for restraint coarser Is passed to avoid fecal sludge is flushed by biologically pre-treated wastewater and thereby the wastewater on the not dissolving ones Parts of the sieve residues reduced is on what the wastewater with particles smaller than 5 mm over a Crossflow cleaning in the room outside the network of a more extensive, upstream denitrification with predominantly anoxic environment is subjected to, in this room also biologically active bacterial sludge and fully nitrified waste water is passed with nitrate oxygen and the nitrate is converted by denitrification into gaseous N and the readily biodegradable carbon is converted into CO2 and thus biodegradable the sewage almost completely is released from nitrogen compounds, as indicated in the following Stages by alternating ventilation and by minimizing air entrainment, another denitrification reaction is reached, wherein the entry of the atmospheric oxygen over a Filtratmengenmessung regulated and after physical elimination of all non-biodegradable substances via ultrafiltration membranes if necessary a physical-technical decolorization and sanitization is performed. Method according to claim 1, characterized in that that the wastewater from the first tank or basin / the first Pit chamber either in the free-level in the following biology room flows and with corresponding height difference brought to the level of Biologieraums by pumping. Method according to Claims 1 and 2, characterized if a pump is required, it will be easier Maintenance separately outside network in the denitrification room. Method according to Claims 1 to 3, characterized that, if inflow into the biology room occurs in the free-standing area, the recirculation pump in the second or a later container / basin and the pump in any case at the same time the sufficient Recirculation of the wastewater and an upstream denitrification ensures. Method according to Claims 1 to 4, characterized that the resulting filtrate either hydrostatically or via a again self-priming conveyor unit is brought to the recovery site with a slight negative pressure. Method according to claim 1, characterized in that that the membranes, if necessary, without limiting the operation of the plant directly with the operator also with chemicals or filtrate and if necessary be backwashed automatically. Method according to claim 1, characterized in that that the process is multi-level. Method according to claim 1, characterized in that that the first stage of the carbon degradation including biologically difficult to decompose Substances such as hormones and endocrine substances and also includes the biological phosphorus removal also includes an alkaline or acid phosphate precipitation is integrated. Method according to claim 8, characterized in that that the phosphate precipitation on the Filtratmenge and the pH is controlled. Method according to Claims 1 to 9, characterized that in the 2nd stage all non-biodegradable substances and complete decolorization (COD <1 mg / l) by the physical elimination (adsorption via activated carbon, adsorber resins or aluminum silicates) with subsequent additional physical sanitation with UV radiation. Apparatus for water recovery or for the purification of waste water, consisting of at least 3 separate, water- and chemical-resistant containers ( 3 . 7 . 9 ) for a cascading operation, wherein the containers are flexible and receive their full volume only in place, a fine-mesh, self-tensioning network ( 2 ) for the retention of coarser substances with a mesh size of less than 5 mm, which is arranged in the entry area of the primary clarifier and adapted in its diameter for taking out and emptying to the size of the manhole of the primary container, a possibly required, arranged in Vorklär- or subsequent container conveyor ( 4 ) z. As a recirculation pump in one of the containers and a plurality of independently operating, alternating, a Filtratmengen Measurement controlled ventilation units ( 5 . 8th . 10 ) for the input of atmospheric oxygen and ultrafiltration membranes ( 11 ) for solid-liquid separation and, if necessary, a physical-technical adsorption and UV irradiation unit ( 13 . 14 ). Device according to claim 11, characterized in that the containers ( 3 . 7 . 9 ) above 1 bar and lined with water or chemical resistant inliners. Device according to claims 11 and 12, characterized in that that the containers are transportable with low volume and in place be unfolded to their full volume. Device according to claim 13, characterized in that that the containers Also suitable for sealing leaking pits. Apparatus according to claim 11, characterized in that a filter surface concentration up to 50 m ² / m ³ container volume is housed. Device according to claim 11, characterized in that that the recirculation pump for easier maintenance separately outside the network in the denitrification room or a subsequent container housed is. Device according to claim 11, characterized in that that the biology room as well as the area of upstream denitrification or the area of solid-liquid separation following the biology room with independent working, alternating ventilation units equipped, wherein the entry of the atmospheric oxygen over a Filtratmengenmessung and over a telemonitored Control unit is regulated. Device according to claim 11, characterized in that the clogging and sludge-free ultrafiltration membranes with highest Packing space saving so are built in that at the lowest Flow height one maximum inflow surface is present. Device according to claim 11, characterized in that that the transport of the resulting filtrate to the place of use either hydrostatic over a control valve or over a self-priming conveyor unit done with a slight negative pressure.